ArticlePDF Available

Abstract and Figures

The first countrywide census of the osprey Pandion haliaetus breeding population in the Cabo Verde Islands took place from December 1997 to September 2001. Since then, about 20 years have elapsed without a new full assessment of the species situation in the country. Yet, some studies and monitoring work have been done in various islands, especially from 2016 onwards. Most notably, long-term monitoring has been carried out on the island of Boavista, recently followed by similar annual surveys on Sal. Although not covering the whole archipelago adequately, data currently available are sufficiently robust for allowing a reliable update of the species situation throughout most of its range and evincing its evolution since the turn of the century. The number of osprey pairs increased remarkably across most of the northern islands, which contain the large majority of the breeding population, while there are apparent signs of some recovery in the southern islands. This growth has presumably resulted from the gradual abandonment of the human harvesting of eggs and nestlings, a formerly widespread practice up to the mid-20th century that has now become rare. The osprey breeding population in Cabo Verde is currently estimated at about 115 pairs, showing an increase of over 30% in the last 20 years.
Content may be subject to copyright.
Zoologia Caboverdiana 8, 1, 03–10
Available at
www.scvz.org
© 2020 Sociedade Caboverdiana de
Zoologia
Artigo original | Original article
Twenty years later: updating the status of the osprey
Pandion haliaetus in the Cabo Verde Islands, West Africa
Luís Palma 1, *, Samir Martins 2, Rosiane Fortes 3, Isabel Rodrigues 4,
Marcos Hernández-Montero 5 & Rui Freitas 3
1 CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Laboratório Associado,
Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal
2 BIOS.CV, Conservação do Ambiente e Desenvolvimento Sustentável, Sal Rei, Boavista, Cabo Verde
3 Faculdade de Engenharia e Ciências do Mar, Universidade de Cabo Verde, CP 163, Mindelo, São
Vicente, Cabo Verde
4 Biosfera I, Mindelo, São Vicente, Cabo Verde
5 Projecto Biodiversidade, Mercado Municipal, Santa Maria, Sal, Cabo Verde
*Corresponding author e-mail: luis.palma@cibio.up.pt
RESUMO
O primeiro censo global da população reprodutora de guincho Pandion haliaetus nas ilhas de
Cabo Verde realizou-se entre Dezembro de 1997 e Setembro de 2001. Desde então, passaram
cerca de 20 anos sem uma nova avaliação da situação geral da espécie no arquipélago. No
entanto, decorreram alguns estudos e trabalho de monitorização em várias ilhas, especialmente
após 2016. É de realçar a monitorização de longo termo conduzida na ilha da Boavista,
recentemente seguida por semelhantes levantamentos anuais na ilha do Sal. Apesar de nem todo
o arquipélago ter sido convenientemente coberto, os dados actualmente disponíveis são
suficientemente sólidos para uma actualização fidedigna da situação da espécie ao longo da
maior parte da distribuição da mesma e para evidenciar a evolução desta desde o início do
século. O número de casais de guincho aumentou de forma notável na maioria das ilhas
setentrionais, que albergam a grande maioria da população reprodutora, enquanto nas ilhas
meridionais indícios de alguma recuperação. Este crescimento resultou provavelmente do
gradual abandono da colheita de ovos e crias nidícolas pelos humanos, uma prática comum até
meados do século XX, que agora se tornou rara. A população reprodutora de guincho em Cabo
Verde está actualmente estimada em cerca de 115 casais, mostrando um aumento de mais de
30% nos últimos 20 anos.
Palavras-chave: Arquipélago, Atlântico Norte, ave de rapina, monitorização, situação actual
Palma et al. 4 Osprey status update in Cabo Verde
ABSTRACT
The first countrywide census of the osprey Pandion haliaetus breeding population in the Cabo
Verde Islands took place from December 1997 to September 2001. Since then, about 20 years
have elapsed without a new full assessment of the species situation in the country. Yet, some
studies and monitoring work have been done in several islands, especially from 2016 onwards.
Most notably, long-term monitoring has been carried out on the island of Boavista, recently
followed by similar annual surveys on Sal. Although not covering the whole archipelago
adequately, data currently available are sufficiently robust for allowing a reliable update of the
species situation throughout most of its range and evincing its evolution since the turn of the
century. The number of osprey pairs increased remarkably across most of the northern islands,
which contain the large majority of the breeding population, while there are apparent signs of
some recovery in the southern islands. This growth has presumably resulted from the gradual
abandonment of the human harvesting of eggs and nestlings, a formerly widespread practice up
to the mid-20th century that has now became rare. The osprey breeding population in Cabo
Verde is currently estimated at about 115 pairs, showing an increase of over 30% in the last 20
years.
Keywords: Archipelago, North Atlantic, raptor, present status, monitoring
INTRODUCTION
The Palearctic osprey, Pandion haliaetus
haliaetus (Linnaeus, 1758) is widely
distributed across Eurasia and the
Mediterranean with projections into the
southern edge of the Palearctic in Africa
(sensu Roselaar 2006), in Cabo Verde and the
Red Sea (Palma et al. 2004, Monti et al. 2015,
Habib 2019). Ospreys are considered resident
in Cabo Verde (Monti et al. 2018a) and show
genetic affinity with northern European
ospreys, so probably originated from birds
wintering in West Africa that settled in the
archipelago (Monti et al. 2018b).
The archipelago of Cabo Verde comprises
10 islands and several islets of volcanic origin
located in the Atlantic about 570 km off West
Africa. Ospreys in Cabo Verde nest from
coastal sand dunes to mountain peaks far
inland (Naurois 1987, Palma et al. 2004), and
live off variable fish diets according to the
island (Martins et al. 2011) and the exposition
to trade winds (Fortes 2016). Apparently,
ospreys have always been widespread in the
north of the archipelago, previously known to
harbour circa 94% of the population
(Palma et al. 2004) and much scarcer in the
south, presumably due to different prey
availability driven by ecological factors
(Naurois 1987). Higher exposition to the
northeasterly trade winds that blow during
most of the year (Duarte & Romeiras 2009)
and to the Canary current is associated with
higher prey availability and richer osprey
diets. This fact provides a possible
explanation for the species higher abundance
in northward and eastward facing coasts at
island scale, and its higher abundance in the
northern islands (Martins et al. 2011, Fortes
2016).
Up to the mid-20th century, Cabo Verde
ospreys were strongly affected by the
overharvest of eggs and nestlings by humans
(Naurois 1969, 1984). This practice decreased
thereafter, allowing numbers to grow from
46–71 in the 1960s (Naurois 1987) to 72–81
pairs towards the end of the century at the
time of the first countrywide assessment,
carried out in 1998 and 1999 with a
complementary survey in Santo Antão in 2001
(Palma et al. 2004).
After 1999, ospreys were surveyed in
Boavista in 2001–2002, with an estimate of
Palma et al. 5 Osprey status update in Cabo Verde
10–14 pairs (López-Suárez 2012), and in
2004–2007 when the number of breeding
pairs grew from 14 to 17 (Siverio et al. 2013).
A partial shoreline survey was also
undertaken in 2003 (Ontiveros 2003). After a
gap in 2008–2011, annual monitoring
resumed in 2012 by the NGO BIOS.CV. On
Sal, after an opportunistic survey in 2016 by
L. Palma, monitoring has been carried out
yearly since 2017 by the NGO ‘Projecto
Biodiversidade’. On São Nicolau, a
comprehensive assessment was done in
January-April 2016 (Fortes 2016). Sectors
uncheckable by land were visited by boat, and
only 6% of the coastline remained
unsurveyed. Old records and osprey-related
place names (see Palma 2017 for
contextualisation) were also checked.
The objective of this work was updating
the osprey population estimate in the country
about 20 years past the 1998–2001 census.
MATERIAL AND METHODS
To update the osprey status in the country we
reviewed all available post-2000 information,
including publications (Ontiveros 2003,
Siverio et al. 2013), theses (Fortes 2016) and
the unpublished yearly monitoring reports of
BIOS.CV and ‘Projecto Biodiversidade’.
Otherwise, surveys were undertaken by the
authors in islands lacking recent information
with the purpose of checking the species
current distribution and numbers, as described
below.
Among the northern islands, São Vicente
was surveyed in March 2016, except for the
southeast coast (circa 20% of the coastline)
due to its inaccessibility from land. Raso and
Santa Luzia were surveyed in April 2016 and
April 2017, respectively. Branco was visited
in May and September 2017 (K. Delgado,
pers. comm.). In the southern islands, only
fragmentary recent data was available.
Therefore, short visits were made to Maio,
Santiago, Fogo, and Brava in May–June 2017
and to Santiago and Maio in June 2019. On
Maio, old records and information provided
by residents and the Maio Biodiversity
Foundation were also checked. Furthermore,
key informants questioned about recent
osprey sightings on Santiago, Fogo and
Rombos provided useful complementary
information (C. Monteiro, N. Barbosa, A.
Leal, A. Veiga, D. Alinho, pers. comm.).
....The reliability of the data available for
updating the numbers of ospreys pairs on each
island was assessed according with the
following data quality categories:
0= anecdotal/ fragmentary data (no update
possible); 1= incomplete survey (unreliable
update); 2= single comprehensive survey
(reasonable update); 3= repeated
comprehensive surveys (reliable update); and
4= systematic annual surveys (very reliable
update).
We used a stepwise approach to calculate
the percentages of change in the population
between 1998–2001 (Palma et al. 2004) and
2016–2019 (present work). First, we
compared the recent (2016 onwards) estimates
in the areas reliably surveyed with those from
the previous survey within the corresponding
areas. Current numbers for Boavista and Sal
were extracted respectively from López-
Suárez (2019) and Hernández-Montero (2019).
Then, we calculated the present
countrywide total estimate by adding to the
recent cumulative estimate: 1) the number of
pairs identified during the previous census
that presumably persist within the areas now
left unsurveyed, i.e. Santo Antão and minor
parts of São Vicente and São Nicolau (see
above), assuming stability as the
precautionary guess (within the general
upward trend); and 2) the numbers suspected
on the islands of the Sotavento. Finally, we
compared the current total estimate with the
previous total to calculate the percentage of
change in the archipelago.
Palma et al. 6 Osprey status update in Cabo Verde
RESULTS
All northern islands with the exception of
Santo Antão were well monitored, so we
consider the respective estimates reliable. The
updating of the osprey population in Santo
Antão was hindered by the lack of human and
logistic resources to tackle the large size and
abrupt relief of the island. In contrast with the
northern islands in general, we considered the
numbers presumed for most of the south
unreliable (Fig. 1), although Fogo, Brava and
Maio were better covered than Santiago.
Fig. 1. Current osprey population estimates and their update reliability in the Cabo Verde Archipelago.
The sizes of the circles are proportional to the estimated number or mean number of pairs (see Material
and Methods for details). Branco and Raso are represented by a common cumulative circle. Numbers in
brackets indicate uncertainty due to incomplete surveys. The darker the grey shading of the islands the
higher the update reliability.
Although variably, the numbers of
breeding pairs increased on most of the
northern islands, from 28 to 37% on average,
and only Santa Luzia and Raso showed
stability or very slight population growth. On
all well-surveyed islands, trends were stable
or positive (Table 1). Overall, the increase
reached on average 35.5% in the area
surveyed and 32.5% in the whole archipelago.
Palma et al. 7 Osprey status update in Cabo Verde
Table 1. Present osprey population estimates (number of pairs) and trends over the last 20 years. (*) Only
six in the area now surveyed; (**) percentages of change were calculated in relation to the area surveyed
and corresponding ends of the interval; (***) see Material and Methods for further explanations. Numbers
in brackets are uncertain.
Island group Island 1998–2001 Present % change**
Northern Santo Antão 18–23 unavailable unknown
São Vicente 8* 13–18 54–67
Santa Luzia 5–6 5–6 0
Branco 12 2–3 33–50
Raso 45 4–6 0–17
São Nicolau 17 18–22 6–23
Sal 4 11 64
Southern Boavista 11 18 39
Maio 1 (2–3) unreliable
Santiago 3–4 (34) unreliable
Fogo 0 (23) unreliable
Brava 0 (0) unreliable
Rombos 0 1 0–100
All In area surveyed 48–51 71–84 32–39
Total*** 72–81 103–125 30–35
DISCUSSION
We showed that the osprey breeding
population in Cabo Verde grew by about one
third during the last two decades, reaching the
present estimate of 103–125 pairs
(considering that there was no increase in
Santo Antão and other unsurveyed areas in the
northern islands). Even though it was not
possible to update the population of Santo
Antão, we assumed that its trend echoes the
situation in the relatively similar nearby island
of São Nicolau, i.e., the population remained
roughly stable or slightly increased due to the
natural protection afforded to nest sites by the
rugged relief.
The southern islands remained poorly
covered due to time and logistic constraints,
especially Santiago because of its larger size
and mountainous landscape. Surveying
Santiago requires considerable time and
resources, aggravated by the fact that some
ospreys may be nesting far from the sea.
There is at least one record from 2008 of a
nest site 3.5 km inland (Cesarini & Furtado
2016). Although further fieldwork is needed
in the south of the archipelago, there are signs
of some recovery from the precarious
situation during the 1960s. For instance, an
osprey nest was observed on Ilhéu de Cima in
June 2018 (N. Barbosa & A. Leal, pers.
comm.), the first on the Rombos Islets since
1965 (Naurois 1987).
The stronger increases are found on the
highly populated São Vicente, as well as on
Sal and Boavista with more accessible terrain
(making nest sites vulnerable). However,
monitoring on Boavista showed inter-annual
fluctuation (17.6 ± 2.1; 14–21 pairs), probably
depending on the ecological conditions in the
early breeding season, ultimately determining
how many pairs attempt to breed, and thereby
can be counted. For example, choosing the 21
pairs of 2016 instead of the 18 pairs of 2019
(López-Suárez 2019) would raise the
population increase rate by 9% (from 39 to
Palma et al. 8 Osprey status update in Cabo Verde
48%). Therefore, calculating trends depends
on the year considered.
Interestingly, the only relatively large
northern island with no apparent change is
Santa Luzia, the only one that long remained
uninhabited. So, we think that the upward
trends observed on most of the northern
islands do reflect the recovery of the species
in the region. To this adds the signs of
recovery in the south. Altogether, there is
strong support for assuming a robust
countrywide recovery from the depleted
osprey population of the mid-20th century,
already evident at the turn of the century
(Palma et al. 2004). Looking back to the
estimates of the 1960s on some smaller
islands and islets that were probably well
surveyed by Naurois (1987), current recovery
seems approaching pre-depletion numbers.
For example, Naurois found only 1–2 pairs on
Raso, no pairs on Rombos, and only two pairs
on Santa Luzia (Fig. 1) stating that 10–20 years
before all 5–6 nests or groups of nests he
observed there were occupied (Naurois 1969).
We think that the update deficiencies did
not affect our countrywide assessment of the
osprey breeding population because present
numbers on Santo Antão are not expected to
be much different from 2001; while in the
south numbers are too low to be influential.
Still, a thorough appraisal of the situation in
the south is of utmost importance, because it
probably represents the species demographic
periphery, possible a population sink, likely to
reflect the overall situation in the archipelago
(Dias 1996). The reoccupation of the area by
recruits from the north would probably
confirm the overall regrowth, whereas the
abandonment of nest sites would probably
mean decline due to depleted recruitment.
CONCLUDING REMARKS
It is important to stress that apart from the
now rare nest raiding, there are no other direct
human behaviours negatively affecting the
osprey in Cabo Verde as we could realise
from our own observations since the end of
the last century. Persecution of adult birds in
particular, may have been fairly uncommon in
the past and is extremely rare nowadays, as
shown by the great tameness of the birds. To
this probably contributed the absence of
shotgun hunting activity in the country. The
situation sharply contrasts with the long
history of systematic persecution in Western
Europe that drove the species to extinction in
many countries during the 20th century,
although there is now a general and steady
comeback to the continent (Palma 2001,
Schmidt-Rothmund et al. 2014). The exception
is on the Canary Islands where the species
continues to decline (Siverio et al. 2018).
On the opposite sense goes the growing
impact of disturbance from tourism-related
activities upon coastal nest sites on Boavista
and Sal that jointly hold almost 30% of Cabo
Verde ospreys (Palma et al. 2004, Siverio et
al. 2013). That often results in breeding failure
and is gradually causing the withdrawal of
nest sites away from the coastline,
undoubtedly a major concern for the species
conservation (Palma et al. 2004, Siverio et al.
2013). Still, the positive population trend of
the osprey in the country represents a good
opportunity to implement preventive
conservation actions, above all focusing on
the control and reversal of impacts from
unregulated tourism-related activities.
Palma et al. 9 Osprey status update in Cabo Verde
ACKNOWLEDGEMENTS
We are indebted to K. Delgado, C. Monteiro,
A. Veiga, D. Alinho, N. Barbosa, A. Leal &
T. Militão for the field data provided and to
A. Vieira, A. Lopes, J. Graça, E. Neves, K.
Lopes, A. L. Tavares, and A. Borges for
helping on surveys. We are grateful to
‘Biosfera I’ and Maio Biodiversity
Foundation, delegations of the Ministry of
Agriculture and the Environment in Maio,
São Nicolau and Sal, and Fogo Natural Park
for the logistic support. We thank Cabeólica
S.A. and BIOS.CV for using data from
unpublished monitoring reports from Boavista,
as to ‘Projecto Biodiversidade’ alike in
relation to Sal. We also thank Cabeólica S.A.
and The International Osprey Foundation for
funding osprey studies and monitoring.
REFERENCES
Cesarini, D. & Furtado, A. (2006) Preliminary
ecological report – Serra Malagueta Natural
Park. Unpublished report, Ministério da
Agricultura e ambiente – Direcção Nacional do
Ambiente, Projecto Áreas Protegidas, Praia,
Cabo Verde, 108 pp.
Dias, P.C. (1996) Sources and sinks in population
biology. Trends in Ecology & Evolution, 11,
326–330.
Duarte, M.C. & Romeiras, M.M. (2009) Cape
Verde Islands. In: Gillespie, R. G. & Clague,
D. A. (Eds.), Encyclopedias of the Natural
World. Encyclopedia of Islands. University of
California Press, Berkeley, USA, pp. 143–148.
Fortes, R.D. (2016) Situação Populacional e
Ecologia do Guincho (Pandion haliaetus) na
Ilha de São Nicolau, Cabo Verde. BSc thesis.
Faculty of Engineering and Marine Sciences,
University of Cabo Verde, Mindelo, Cabo
Verde.
Habib, M.I. (2019) Breeding Status of Ospreys in
Egypt (Red Sea) from 2012 to 2018. Raptors
Conservation, 38, 43–58.
Hérnandez-Montero, M. (2019). Estudo e
Conservação do Guincho – Pandion haliaetus
– na ilha do Sal, 2019. Unpublished report,
Associação Projeto Biodiversidade, Santa
Maria, Ilha do Sal, Cabo Verde, 11 pp.
López-Suárez, P. (2012) Bird population
monitoring report: ospreys and red-billed
tropicbirds on Boa Vista Island (December
2011–May 2012). Unpublished report, ONG
Cabo Verde Natura 2000, Sal-Rei, Cabo Verde,
15 pp.
López-Suárez, P. (2019) 8th Bird population
monitoring report: Boa Vista 2019,
Unpublished report, BIOS.CV, Sal-Rei, Cabo
Verde, 41 pp.
Martins, S., Freitas, R., Palma L. & Beja, P.
(2011) Diet of Breeding Ospreys in the Cape
Verde Archipelago, Northwestern Africa.
Journal of Raptor Research, 45, 244–251.
Monti, F., Delfour, F., Arnal, V., Zenboudji, S.,
Duriez, O. & Montgelard, C. (2018b) Genetic
connectivity among osprey populations and
consequences for conservation: philopatry
versus dispersal as key factors. Conservation
genetics, 19, 839–851.
Monti F., Duriez, O., Arnal, V., Dominici, J.M.,
Sforzi, A., Fusani, L., Grémillet & D.
Montgelard, C. (2015) Being cosmopolitan:
evolutionary history and phylogeography of a
specialized raptor, the Osprey Pandion
haliaetus. BMC Evolutionary Biology, 15, 255.
Monti, F., Grémillet, D., Sforzi, A., Sammuri, G.,
Dominici, J.M., Triay Bagur, R., Muñoz
Navarro, A., Fusani, L. & Duriez, O. (2018a)
Migration and wintering strategies in
vulnerable Mediterranean Osprey populations.
Ibis, 160, 554–567.
Naurois, R. de (1969) Notes brèves sur l’avifaune
de l’archipel du Cap Vert. Faunistique,
endémisme, écologie. Bulletin de l’Institut
Fondamental d’Afrique Noire. Tome XXXI,
série A, 1, 8–218.
Naurois, R. de (1984) Contribution à l’ornithologie
de l’archipel du Cap Vert: reproducteurs
menacés d’extinction, nicheurs occasionnels,
oiseaux mentionnés par erreur. Boletim do
Museu Municipal do Funchal, 36, 38–50.
Naurois, R. de (1987) Le balbuzard (Pandion
haliaetus) aux îles du Cap Vert. Annali del
Museo Civico di Storia Naturale, 86, 657–682.
Palma et al. 10 Osprey status update in Cabo Verde
Ontiveros, D. (2003) Nesting distribution, food
habits, and conservation of Osprey on Boavista
Island (Archipelago of Cape Verde). Journal of
Raptor Research, 37, 67–70.
Palma, L. (2001) The Osprey Pandion haliaetus on
the Portuguese coast: past, present and
recovery potential. Vogelwelt, 122, 179–190.
Palma, L. (2017) Tracking the ancestral
Portuguese name of the Osprey across the
Atlantic: hints from language, literature,
history and geography. Arquivos de Zoologia
(S. Paulo), 48, 115–130.
Palma, L., Ferreira, J., Cangarato, R. & Pinto, P.
V. (2004) Current status of the Osprey in the
Cape Verde Islands. Journal of Raptor
Research, 38, 141–147
Roselaar, K.C.S. (2006) The boundaries of the
Palearctic region. British Birds, 99, 602–618.
Schmidt-Rothmund, D., Dennis, R. & Saurola, P.
(2014) The osprey in the Western Palearctic:
breeding population size and trends in the early
21st century. Journal of Raptor Research, 48,
375–387.
Siverio, M., López-Suárez, P., Siverio, F.,
Rodríguez, B., Varo-Cruz, N. & López-Jurado,
L.F. (2013) Density, nest site characteristics
and breeding rates of the Osprey (Pandion
haliaetus) in the southern limit of its range in
the Western Palearctic (Boavista, Cape Verde
Islands). African Journal of Ecology, 52, 50–58.
Siverio, M., Siverio, F., Rodríguez, B. & Del
Moral, J.C. (Eds) (2018) El águila pescadora
en España y Portugal: población invernante
20162017, reproductora en 2018 y método de
censo. SEO/BirdLife. Madrid, Spain,103 pp.
Received 22 November
2019
Accepted 3 1 December
2019
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
A new series of Osprey surveys started in early June 2012 and ended in July 2018. The main goal was to survey the local resident breeding Ospreys Pandion haliaetus haliaetus. I also visited the three wintering areas Malaha, Aswan and Lake Nasser. We found breeding and nesting Ospreys in most of the visited Islands at the Red Sea, with nests placed mostly on sand dunes but also on roof tops. A total of only 40 pairs were confirmed breeding in the Red Sea and South Sinai provinces and 16 non-local Osprey were observed at the wintering sites which make Egypt important as a stopover area for Osprey during Spring and Autumn migration. The breeding season of the Osprey in the Red Sea starts from the first week of December in the south of Egypt to the first week of January in the north of Egypt. Osprey’s diet consists entirely of fish and their mainly forage at reef flats and reef edges. Birds from the resident Red Sea population tends to be distinctly smaller and lighter in plumage than birds from the European population. The main threat to the breeding population is human disturbance on the Red Sea coasts and islands. A further artificial nests project at Red Sea Coast is highly recommended to replace the lost nests because of tourism development and increase the Egyptian population to the previous level.
Article
Full-text available
Genetic variability and population structure in osprey were studied using DNA microsatellite markers. Special emphasis was placed on the subspecies living in the Afro-Palearctic (Pandion haliaetus haliaetus). For comparative purposes, American osprey subspecies (P. h. carolinensis, P. h. ridgway) and Indo/Australian subspecies (P. h. cristatus) were included in this analysis. 20 DNA microsatellite loci were analysed across a total of 200 individuals. Cluster analysis of genetic distances generally grouped populations of osprey in accordance with their subspecific designation and with previous results from mtDNA analysis. Ospreys from America and Australia were clearly separated from P. h. haliaetus suggesting a more ancient isolation which prevented recent gene flow across these groups. Within P. h. haliaetus, significant genetic differentiation was found between populations in northern and southern Europe, suggesting that the Afro-Palearctic group is structured into two interconnected entities (Mediterranean and continental Europe). Population structuring was supported by an assignment test and by analysis of allele-sharing among individuals. At the Mediterranean scale, no significant differences of allelic information were found between populations. Behaviours such as dispersal, migration and philopatry seem to have played simultaneously and in contrary directions in shaping the genetic structure and diversity of populations. Our results provide essential information for reconstructing gene flow and genetic variability among osprey populations at different scales, which call for caution in the proactive management and conservation of the species, namely in the Mediterranean area.
Article
Full-text available
Guincho, the traditional Portuguese name of the osprey (Pandion haliaetus) is unique and ancestral. It is found in several sorts of fictional literature from the 16 th up to the early 20 th centuries in the form of a metaphor born from an old popular proverb. The first time the name appears as the vernacular designation of the osprey is in a 17 th falconry treatise, and then in old dictionaries and early ornithological monographs and catalogues throughout the 18 th to early 20 th centuries. In Portugal, however, the name barely survives, partly due to the species demise in the country during the 20 th century, but mainly because it was gradually replaced by an erudite term in ornithological literature since the middle 19 th century. However, given the conspicuousness of the species and its nests, the name and its composites are retained in a number of places along the coast. And, following the Portuguese diaspora of the 16 th-18 th centuries, the term spread to the archipelagos of Madeira, Cape Verde and the Canaries where it impregnated the local vocabulary and again gave the name to many coastal places. Then, it moved from the Canaries to the Spanish speaking areas of the Caribbean riding the mass migration of Canary Islanders to the new colonies. In consequence, the traditional Portuguese name of the osprey is still fully used in several island countries across the Atlantic. The remarkable presence of the ancestral Portuguese name of the osprey in language, literature and geography allows its rehabilitation as the proper popular name of the species and sanctions its legitimacy as a tool for reconstructing the ancient historical ranges of the osprey. Ultimately, revaluing the name is also a matter of cultural preservation , which compliments and enriches the current efforts for the species recovery in Portugal.
Article
Full-text available
Background: The Osprey (Pandion haliaetus) is one of only six bird species with an almost world-wide distribution. We aimed at clarifying its phylogeographic structure and elucidating its taxonomic status (as it is currently separated into four subspecies). We tested six biogeographical scenarios to explain how the species' distribution and differentiation took place in the past and how such a specialized raptor was able to colonize most of the globe. Results: Using two mitochondrial genes (cyt b and ND2), the Osprey appeared structured into four genetic groups representing quasi non-overlapping geographical regions. The group Indo-Australasia corresponds to the cristatus ssp, as well as the group Europe-Africa to the haliaetus ssp. In the Americas, we found a single lineage for both carolinensis and ridgwayi ssp, whereas in north-east Asia (Siberia and Japan), we discovered a fourth new lineage. The four lineages are well differentiated, contrasting with the low genetic variability observed within each clade. Historical demographic reconstructions suggested that three of the four lineages experienced stable trends or slight demographic increases. Molecular dating estimates the initial split between lineages at about 1.16 Ma ago, in the Early Pleistocene. Conclusions: Our biogeographical inference suggests a pattern of colonization from the American continent towards the Old World. Populations of the Palearctic would represent the last outcomes of this colonization. At a global scale the Osprey complex may be composed of four different Evolutionary Significant Units, which should be treated as specific management units. Our study brought essential genetic clarifications, which have implications for conservation strategies in identifying distinct lineages across which birds should not be artificially moved through exchange/reintroduction schemes.
Article
Full-text available
Pandion haliaetus en El Oeste Paleártico: Tamaño de La Población Reproductiva Y Tendencias A Comienzos Del Siglo XXI El número de parejas nidificantes de Pandion haliaetus registradas en Europa, el norte de África y Oriente Medio ha alcanzado entre 9500 y 11 500 a comienzos del siglo XXI. Comparado con los números de la década de 1980 (ca. 5500 pares), la población casi se ha duplicado. El incremento es más obvio en países como Alemania y el Reino Unido. Las poblaciones europeas más grandes e importantes en Suecia, Finlandia y Rusia parecen ser estables. En contraste, Portugal, España continental y Turquía perdieron sus últimas parejas reproductivas en las décadas de 1980 y 1990. También fueron reportadas tendencias negativas en Polonia debido a la persecución y en el sudeste europeo y norte de África, donde sólo quedan pocas parejas. Las reintroducciones en Inglaterra, España e Italia han resultado en unas cuantas parejas reproductivas nuevas en años recientes.
Article
Although the western and eastern boundaries of the Palearctic region are widely agreed, there is still much debate about the southern boundary. In an attempt to establish a definitive southern boundary, the distribution of 1,037 breeding passerine species in the Palearctic, and adjacent parts of the Afrotropical and Oriental regions north of 5°N, were analysed. The WorldMap computer program was used to combine these maps, to reveal species richness. The variations in the position of the southern boundary suggested by previous authorities gives rise to three zones: north of the northernmost boundary, which is unequivocally Palearctic; south of the southernmost boundary, which is unequivocally Afrotropical or Oriental; and a border region in between, which is analysed in detail here to establish an objective southern boundary for the region.
Article
Between 2004 and 2007, we studied density, habitat features and breeding parameters of the osprey (Pandion haliaetus) population in Boa Vista Island (Cape Verde). A total of 79 nest structures were identified, 37 of which were occupied for at least 1 year during the study period. The osprey population ranged between 14 and 18 pairs, and the mean density and distance between neighbouring occupied nests were 2.58 pairs per 100 km2 and 3089 m, respectively. Occupied nests were found to be significantly further from the coastline and roads than unoccupied nests, but the distances from villages were similar. The majority (81.1%) of the 37 occupied nests were easily accessible to humans. Mean clutch size was 2.59, average productivity was 0.76 young/active nest, and breeding success was 58.8% [Correction added on 13 May 2013, after first online publication: the average productivity was changed from 0.72 to 0.76]. Density in Boa Vista was higher than that in other sedentary island populations in the Western Palearctic, whereas the productivity was the lowest of this region. Clutch size did not vary among Western Palearctic populations, but the differences observed in productivity were likely influenced by local factors that in Boa Vista are attributed to nest depredation by the brown-necked raven (Corvus ruficollis) and to direct human persecution.